The present invention relates generally to plumbing apparatus, and more particularly, to sanitary appliances such as water-closets and the like. The invention is directed to the provision of means to be fitted to the outlet pipe of a water-closet or like appliance, such as a urinal, by means of which the flushing action of the appliance may be enhanced and improved.
Flushing of water-closets uses considerable quantities of water, which is usually drawn from supplies of generally drinkable quality. In an average household a water-closet may be flushed 12-16 times for each twenty-four hour period. Moreover, members of a given household will ordinarily use water-closets away from the home, such as in an office or factory.
Most closets require 9 liters of water or more for each flushing, such a quantity of water being considered necessary for displacement of waste matter from a water-closet pan through the discharge pipe. The term "waste matter" is meant to include all kinds of non-fluid refuse, having a density of about 1.0, which are normally removed by way of water-closets from residential houses and other premises. Not only faeces and toilet paper, but also baby napkins, paper towels, sanitary towels, rags and other refuse materials are flushed down water-closets as waste matter.
Studies of the displacement of waste matter through nearly horizontal discharge pipes have led to the observation that such pipes are almost never filled to more than 50%. As a result, some authorities taking into account regulations for the fall of such pipes, have decided to allow a flush water volume of 6 liters for water-closets. This involves closets connected to municipal sewage disposal systems wherein the pipes can have a fall of down to 3%. To make such pipes self-cleaning, the rate of flow therethrough must be a minimum of 0.6 m/second at a continuous flow.
In more rural or less populated areas, cesspools may be utilized for waste disposal in place of hook-ups to municipal water supply. In such areas, the degree of fresh water consumption of the closets is not the main problem. However, it is more important to reduce the quantity of soil water which has to be collected in a cesspool, removed by a suction pump on a container lorry and then taken to the municipal sewage treatment plant.
Some known water-closets are simply flushed with water by means of sub-atmospheric pressure in the discharge pipe without using an air stream as an aid to displacement of the waste matter. Such washdown closets may work with flush water quantities of only about 3 liters and, with such low amounts of flush water, discharge pipes with a somewhat smaller diameter are used, viz. 75 mm instead of 100 mm in conventional discharge systems. The consequence is that the displacement capacity of such a system is low, which means that the distance between the closet and the cesspool has to be restricted, in general to less than 20 m, even if the fall of the pipe is considerable.
One way of improving the flushing of a water-closet, so as to prevent part of the waste matter from remaining in the trap and requiring the user to flush a second time, is to produce a water-plug in the discharge pipe. A water-plug is the type of device which moves down a pipe and as it does so it produces behind it a sub-atmospheric pressure which sucks the remaining water and waste matter out of the trap. In water-closets utilizing a water plug, there may need to be provided means for supplementary filling of the trap in order to make up the water-seal. This may be accomplished, for example, by a branch pipe from the water-supply pipe of the water-closet cistern.
The present invention is intended to provide simple means whereby practically any water-closet with a so-called S-trap can be made to operate with a low volume flush thereby to reduce water consumption. Preferably with such means it should be possible to lead the discharge pipe in any horizontal direction and the means should be easily installed within the dimensions available with floor beams as now used.